From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=74.125.82.47 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794726812; b=kVs/Vl95qv36Uwnnqp35NhTpTiWsl/jHJeKad5/ZxCpzKpXUkx1Xz3Jn6tIgGXGlINNB gitshIWG1QxIzTUZALf1+RWiGpkIogA5HTNxHccLloJlQRX1r6fzZ15n8bJaj0aFxsLF/ IRHbwAW3deDH7XawPmTtX87LhWguymT4PcbFc87LTjRqfF3RmY9W7KvPbIlxy/fsW3HQC 1vDhc7t+f1Hlbb+CCimAcsFDViXyi3XYf0dXe6sNd/rMixgxD3TGkTnrhB87sb1bXaZq/ SYnGZR3hnTGRaxx+CL7mUUrGA2/8DBz6RnGbqcW19V7rxvnaWOKDkAcy9SN70AoaGlw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794726812; h=DMARC-Filter:Received:DKIM-Signature:X-Google-DKIM-Signature: X-Forwarded-Encrypted:X-Gm-Message-State:X-Gm-Gg:X-Received:Received: From:To:Cc:Subject:In-Reply-To:Date:Message-ID:References: MIME-Version:Content-Type:Content-Transfer-Encoding; bh=i0sztYeDoa78GRxByi5DPGRDZ13zK/I8mczcB1W5Z+o=; b=fmkFFJXKLNyQtFT6nup7EEd3+OD7SL5SmHmsBVnZGZxmWPwVLjmFPIW3pE8T8iLDX5Y5 q9OK0ezCeF8f/X1seTlDYJ+yYTUdlTtWDeTHsWRW4rXj+mE32jkux3U7NJRz7bD5PWVO/ C+BJ2stjOqM7G/pDjfS5AQeaZZnHwX0K/etWwxseajY92iSEVeat/2WgSCgI0idz8cVLD SwHbUp55v/VOJCZvZ2F82MvIzNH15m1rfdIcl4jemuzQ6OIpYG6bDgGrYd6OMPraJk5XV wKahxwtrLNJ3YZBjpdvJn27T2qUbJ/TdcsE21GRoTv6wYJFOW8sq9boIBTFwVPD5Z/w== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20260707 header.b=f0EKiv+f; arc=none smtp.remote-ip=74.125.82.47 Received: from mail-dl1-f47.google.com (mail-dl1-f47.google.com [74.125.82.47]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 66015606A331 for ; Sun, 15 Nov 2026 07:13:32 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 66015606A331 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20260707 header.b=f0EKiv+f Received: by mail-dl1-f47.google.com with SMTP id a92af1059eb24-1a2761c69fbso2761587c88.0 for ; Sat, 14 Nov 2026 23:13:32 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20260707; t=1794726811; x=1795331611; darn=vger.kernel.org; h=content-transfer-encoding:content-type:mime-version:references :message-id:date:in-reply-to:subject:cc:to:from:from:to:cc:subject :date:message-id:reply-to:content-type; bh=i0sztYeDoa78GRxByi5DPGRDZ13zK/I8mczcB1W5Z+o=; b=f0EKiv+f25sXRcQmBoiK+WsCsclD9PQHa+U5z3sGf3KR1sS3ZNEEroqRh6RNiac07P vGJPEugwLNmQaWqJhCPHikaN8XT33PRVwWCxE9PqkkLJA6butk39sYE2ryU8qCsIMdGI yo50td1Os6it0j1WrNa5HxnLEw4W7aO/qgSsYPJply/RpIro6UCSg0Mbr4ks/thyRkDc jq1OBKLqGUt/bM6QVBsbrIsF1mbjoO/AbvtSri1zHl8+S2Sf3KoNhgqJldsJW2yIuTc5 6FJrXgJQKS6UwdWBKS3YQ4l597qJpRKbmN+vGilzta6Rl47F1I/gy3R+i3U13Lj6DU+d z+8g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1794726811; x=1795331611; h=content-transfer-encoding:content-type:mime-version:references :message-id:date:in-reply-to:subject:cc:to:from:x-gm-gg :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to :content-type; bh=i0sztYeDoa78GRxByi5DPGRDZ13zK/I8mczcB1W5Z+o=; b=gGFwEFV0+f3Ru0XndtXi2QfuhOaLI1zVt5riSz+gaEW1Hk0ZZaYOICbmDVy5ppwFre r7+VuqIpHTS1y/yCNbon9XiE5RaI0zSaaqd8unEdtdsYPrIT8Ir58uJMLOW6dNmPxZC9 AGonuoKH9ID9XEdP7lplchoPawJYQ4CAGWHapBCKAEDBZVxLl37vx3B3FlUqbE7NZ9Gh fbpiONDleIZ2ZLUdJITc1K3VpM7Jkp57qpAhipaG+Ijfc7tFIzOgIl+4kwDcI/bnCT0I H+rQs+gkaPigaKRCzdkrkH2nYc4aFpqchQMXdjQJhh+DJqt9woMwrx8BM5FRtABqgrif TxFg== X-Forwarded-Encrypted: i=1; AL+hErGEmm8iC+B8P1x7vNMZ1ij9n6unwaMlylSvZb4lxbM47ZOnfwpJsDr0cDM6m1j/WzyA7Bltr8L2wsTiXcc0@vger.kernel.org X-Gm-Message-State: APuU4Z/EaEauJRRbd1AbYofos2Mo16UJC+Dt+o59X3cbBoIaPCXoTb25 szP6KXUGYZVAlADAcEh0oOIc8Cz3fzbhjR2r9n9eCef8avWDjIcjY5n7 X-Gm-Gg: AYBFou29B64op7HAPtnMVqGYNnIlPNTDq47Run0uZN0iL8ucvzJyTsVe1HOJZctyRMk Z4jMPhzabxQ1KgltA8d66ChFD5RhjR8wlCtlQSQ59huJQnNHJh6eBNBh4D/nhLVrjpCFKRBdCzr VckWpHX1f+vEn2kgX/qLcuXeoocHKBlUxj6StgVbXTYLnVFDcVKzlZWPgY4UfXFafyZuDWyu4Uo PkZQ96S4nB9z+7eIsPERTwZ45On9NehRsj950IzycItWHuHK9ges32eoS5ent4hxmuK6YOjGR6E zoVhUtIEgu4W0z3asqJleRccZRXE9Hc6yMbNaLY3vjsoRw4x+2kp5qnRqhhWcrNV9ZwO/OnY3jJ mducK/6VFkdcARJPGJxBnfh73YYUgEZ87IaHkTzsOI7Fo6jT6QAB4dLqGpSiX2ZP8UoToKH3ssv B/w/Gw8q879FpsLyHtav5EjN8sUbyZd0/ZVF5GsklMIfwxS44Kwclsdu8XH8qtcOWQOs5Lpd72G A8wpotFaQaREf6DIm9cIh0YggO73WJFGQi5qdsSVjNEmFPiA0hwjCv4E/PXxjPkyQ5QTB/dGd5g NvxT+rcVyfBGGug0w24YJkjdbMs= X-Received: by 2002:a05:7300:6148:b0:36a:7bb7:4609 with SMTP id 5a478bee46e88-37967dd7e1dmr11471490eec.34.1794726811302; Sat, 14 Nov 2026 23:13:31 -0800 (PST) Received: from pve-server ([49.205.216.49]) by smtp.gmail.com with ESMTPSA id 5a478bee46e88-37956bad134sm27441185eec.27.2026.11.14.23.13.17 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 14 Nov 2026 23:13:30 -0800 (PST) From: Ritesh Harjani (IBM) To: Mike Rapoport , "Christophe Leroy (CS GROUP)" Cc: linux-kernel@vger.kernel.org, Alexandre Ghiti , Andrew Morton , =?utf-8?B?QmrDtnJuIFTDtnBlbA==?= , Catalin Marinas , "David S. Miller" , Dinh Nguyen , Donald Dutile , Eric Chanudet , Heiko Carstens , Helge Deller , Huacai Chen , Kent Overstreet , Liviu Dudau , Luis Chamberlain , Mark Rutland , Masami Hiramatsu , Michael Ellerman , Nadav Amit , Palmer Dabbelt , Peter Zijlstra , Philippe =?utf-8?Q?Mathieu-Daud=C3=A9?= , Rick Edgecombe , Russell King , Sam Ravnborg , Song Liu , Steven Rostedt , Thomas Bogendoerfer , Thomas Gleixner , Will Deacon , bpf@vger.kernel.org, linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mips@vger.kernel.org, linux-mm@kvack.org, linux-modules@vger.kernel.org, linux-parisc@vger.kernel.org, linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, loongarch@lists.linux.dev, netdev@vger.kernel.org, sparclinux@vger.kernel.org, x86@kernel.org, Madhavan Srinivasan Subject: Re: [PATCH RESEND v8 11/16] powerpc: extend execmem_params for kprobes allocations In-Reply-To: Date: Sun, 15 Nov 2026 12:33:31 +0530 Message-ID: <4idi8tks.ritesh.list@gmail.com> References: <20240505160628.2323363-1-rppt@kernel.org> <20240505160628.2323363-12-rppt@kernel.org> <3f7af771-87a7-4ae7-9919-bc4c23bd31c9@kernel.org> X-Mailing-List: linux-modules@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Mike Rapoport writes: > Hi Christophe, > > On Fri, Nov 13, 2026 at 03:36:01PM +0100, Christophe Leroy (CS GROUP) wro= te: >> Hi Mike, >>=20 >> Looks like I missed this change ... >>=20 I didn't initially get what Christophe meant here. Then I came across this reply of from him[1]. So looks like somehow between v3 to v8, something got changed?=20 On powerpc book3s/32, vmalloc space is not executable. Only modules=20 space is executable. X/NX cannot be set on a per page basis, it can onl= y=20 be set on a 256 Mbytes segment basis. See commit c49643319715 ("powerpc/32s: Only leave NX unset on segments= =20 used for modules") and 6ca055322da8 ("powerpc/32s: Use dedicated segmen= t=20 for modules with STRICT_KERNEL_RWX") and 7bee31ad8e2f ("powerpc/32s: Fi= x=20 is_module_segment() when MODULES_VADDR is defined"). So if your intention is still to have an executable kprobes, then you=20 can't use vmalloc address space. [1]: https://lore.kernel.org/all/1cb41761-29d0-5d33-b7c1-0ca3acaa810d@csgro= up.eu/ >> Le 05/05/2024 =C3=A0 18:06, Mike Rapoport a =C3=A9crit=C2=A0: >> > From: "Mike Rapoport (IBM)" >> >=20 >> > powerpc overrides kprobes::alloc_insn_page() to remove writable >> > permissions when STRICT_MODULE_RWX is on. >> >=20 >> > Add definition of EXECMEM_KRPOBES to execmem_params to allow using the >> > generic kprobes::alloc_insn_page() with the desired permissions. >> >=20 >> > As powerpc uses breakpoint instructions to inject kprobes, it does not >> > need to constrain kprobe allocations to the modules area and can use t= he >> > entire vmalloc address space. >>=20 >> Using breakpoint means the segment must still be executable. >> On book3s/32 VMALLOC segment is not executable, while module segment is. >>=20 >> See commit 6ca055322da8 ("powerpc/32s: Use dedicated segment for modules >> with STRICT_KERNEL_RWX") >>=20 >> See report and fix at https://lore.kernel.org/all/ed03d290d440d579a81ae0= b7de5243721291d903.1794543909.git.ritesh.list@gmail.com/ > > I'll take a look, thanks! >=20=20 Thanks Mike for taking a look. Sorry, I should have ccd'd you there, I guess I missed it. However, the changes are these one here [2][3] [2]: https://lore.kernel.org/linuxppc-dev/82c4973addebd82923c460cb44221f5b7= 6146afe.1794572365.git.ritesh.list@gmail.com/ [3]: https://lore.kernel.org/linuxppc-dev/f75f2cf97f44375fd2c8820e0caeab703= cdb371c.1794572365.git.ritesh.list@gmail.com/ -ritesh